Currently in beta

Only study moves you'll actually face.

Build your opening repertoire, check it against real game data at your rating, and drill the gaps with spaced repetition until they're automatic.

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Your repertoire — coverage
Sicilian Defence, Open 71%
Gap found — 4...Nc6 appears in 1 in 60 games at your rating. No response prepared.

Real coverage data from your repertoire, calibrated to your rating band.